The present disclosure relates to a semiconductor structure, and particularly to an InGaN-based light emitting diode employing an elemental semiconductor material contact and methods of manufacturing the same.
A multi-quantum well including alternating layers of indium gallium nitride and gallium nitride can be employed to provide light-emitting diodes. The wavelength of the light emitted from such a light-emitting diode can be tuned by adjusting the content of indium in the indium gallium nitride layers. The amount of indium that can be incorporated into the indium gallium nitride layers is limited by the thermal instability of the indium gallium nitride material. Specifically, if the atomic concentration of indium in an indium gallium nitride material exceeds 17%, thermal segregation can occur within the indium gallium nitride material when the temperature is raised above 600° C. During the thermal segregation, indium in the indium gallium nitride alloy segregates from the alloy to form indium portions and remnant indium gallium nitride alloy portions including indium at an atomic concentration lower than 17%. The periodicity in the multi-quantum well is destroyed, and the light-emitting diode becomes nonfunctional in such cases.
Because metallization processes on gallium nitride materials require temperature processing at elevated temperatures ranging up to 1,000° C., use of indium gallium nitride layers having an atomic concentration of indium greater than 17% has been impossible so far. As a result, the wavelength of light that can be emitted from light-emitting diodes employing a multi-quantum well including an indium gallium nitride layer has been limited to mostly ultraviolet radiations.